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J. W. BABLOW, OF -.UNITED STATES ARMY.

Letters Patent No. 72,358, dated December 1 7, 1867.

IMPROVEMENT IN TRIPoDs ron summum-INSTRUMENTS..

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To ALL AWHoM 1T MAY eoNcERN;

Be it known that I, J. W. BAnLoW, Captain-'Corps of Engineers, United States Army, have invented an Improved Tripod for Surveyors and Engineers. Use; and I do hereby declare that the ,following is a full and exact description thereof, reference being had to the accompanying drawings, making part of this specification- Figure 1 being a top view of a tripodprovided with my improvement.

Figure 2, a central vertical section thereof, in a plane indicated bythe line z g. 1.`

Like letters designate corresponding parts in both figures.y

The nature oi`- my invention consists in a means of adjusting an instrument laterally, in any direction,

'upon the tripod, withoutvmoving or disturbing tbe latter.

In applying'the principle of this invention, I contemplate, as a suitable means, t-he addition of adjustable plates, B B, to the top or table A of the tripod. By having the central part, b, of the tripod-table eut away, as indicated in the drawings, and passing an adjusting-screw, C, through this and the adjustable plates B B, the object desired is simply and eifectually accomplished. In this case, the adjusting-plates B B shouldbe large enough toallow the' adjustment without losing their support over the tripod-table. To complete the device,-as`

represented, a tightening-nut, D, should be usedto secure the adjusting-plates in any position required. Any device equivalent `in effect to the plates B B may henusediu their stead.

AForthe'purpose of accurately locating the ,centre-of the instrument over a given point by the use of a plumb and line, a vertical aperture, d, is madedown through the centre of the clamping-screw C and nut D; or, otherwise, through the centre ofthe adjustable-plates, in' which aperture the plumb-liue lis suspended'. By means of this, the position required can be obtained very accurat'. ely.

The method of using my invention is obvious'. The tripod-legs a a having been located in a position vapproximating to that required, and the tripod-table A properly levelled at the same time, theexact required position ofthe instrument is obtained by adjusting the plates B B laterally, and finally'secured by tightening the nutfD.

What I claim as my invention, und desirel to secure by Letters Patent, is-

Producing lateral adjustment ou the tripod by means ofthe clamping-plates or surfaces B and. the= tightening-screw C, substantially as and for the purpose herein specified.

I also claim the central vertical aperture d through the adjusting-serewand nut, and through the'adjustingplate, for applying a'plumb and line, substantially as set forth., 'i

The above specification of my improved tripod signed by me, this 20th day of March, 1867.

' .J. W. BARLOW. Witnesses:

SoUTnARD HOFFMAN, Fluent. R. KENT. 

